To begin the quest, the speaker next to the elevator in Vera Keyes' suite must hear the password in Vera's voice. The Courier can take the holotape of Vera's audition, go down to the front computer in the main lobby, collect all three music varieties, and return to the elevator in Vera Keyes' suite. Play the music into the speaker, and the elevator can now be taken to the lower level. Alternatively, if one has not killed Christine, she will say the password using her new vocal cords after recovering the music from the lobby computer.

The Courier must navigate a maze of ducts and catwalks filled with security holograms, toxic clouds and many shielded speakers. In some situations, the Courier may have to trigger hologram monitors to clear a path. Once passing through the two initial vault doors, on the right is a terminal next to another vault door. Enter the duct maze by using vault maintenance access terminal to open the maintenance access. There's a speaker nearby. Follow the passageway around to the first room. Entering the first chamber, the speaker is immediately in front of the Courier. Halfway down the chamber the Courier enters the range of another speaker. Jump down the broken walkway and then to the right to enter the shelter. There is a safe spot in front of the table in the enclosure with the worker's note complaining about safety and Frederick Sinclair's ignorance of the vault issues. There are two ammunition boxes next to the note on the shelf. Continue through the passageway to the left.

Follow the passageway around and into another shelter area. In the next room are four speakers, two of them unshielded. Exit the sheltered area to the right, go up the stairs, jump over the broken walkway and the safe spot is in the corner. Directly behind the Courier above the door they came through is an unshielded speaker. Slightly to the right and up high above a doorway is the second unshielded speaker. Destroy both of the unshielded speakers.

A third, shielded speaker is high on the wall just a bit further along the catwalk. If the Courier's gun is holstered, they'll have barely enough time to run down the left side of the upper walkway and reaching the terminal to override the alarms. Continue through the corridor.

Note: On the right broken section of the top walkway, one can actually jump onto the beam and then onto the section with the exit. If one's timing is good then this is an easier way to get through than to follow the left path. If one lands on the beam and run to the right towards the wall, they can step out of reach of the speakers, resetting the collar timer.

Once the alarms are off, standing next to the console walk to the edge to see the roof of the shelter the Courier just ran from, if they can, fall onto that and there will be a duffle bag and inside will be a random small gun and some other Items.

The next room adds security holograms to the gauntlet. The hologram control computer is in a workers' hut to the left of the entrance to this area across a walkway with a gap in it. There are 3 hologram emitters in this room, although they require a Repair skill of 100 to disable, the Courier can shoot them. The first is on top of the enclosed structure to the left (when entering the room). The Courier can push a barrel onto the catwalk to the left, jumping on it and jumping in the air while on the barrel will allow them to shoot the emitter on the roof of the first structure (After moving said barrel, it will disappear and become visible again after touching it and will repeat in this way), alternatively this can be achieved by exiting the room towards the gap in the walkway the Courier came from, hopping onto the rail and attempting a jump shot into the emitter, this will make the holograms hostile so run. The second is on top of the metal beam almost directly on top of the door with the force field. The Courier will need to run along a beam and jump up onto the roof of the structure in the southeast corner of the map to reach these. The third is on the ceiling (not the roof like the 1st, but inside) of the control structure in the northeast corner of the map. The Courier can also use 2 or 3 carefully tossed hand grenades to blow up the emitters without having to get close to the holograms or the speakers (one can get up to 9 frag grenades from the grenade bouquets that Dean Domino set up around himself from where the Courier first encounters him, so long as they can pass an Explosives check (30) to disarm the grenades). Alternatively, one can run from the southeast structure to the northeast structure and shoot it, running back quickly, but you will have to be very fast, as this method puts you in danger of the radios for under a second less than the time needed for your collar to detonate (or one could run past the last security and turn off the alarms first, then run into the adjacent room where the emitter is). After dispatching the three hologram emitters, the Courier can turn off the security system at the last terminal. There is a terminal in a shelter on the lower catwalk on the other side of the room. This allows them to turn off all alarms.

After the room is quiet, drop down to the lower catwalk in the poison gas and grab the Vault turret terminal password tape. Activate the vault security turret terminal password as this shuts down the last set of force fields and speakers.

After entering the hall past the force fields, there is the vault security terminal which can be used to shut down the remaining security. (Note: Initially there are only two options: "Vault Security Protocols Information" and "Vault Security Protocols Warning," but after reading the first entry another option to disable security comes up.)

Immediately before entering the vault is a toolbox and next to it, a holotape containing a venomous message to Vera Keyes. A skeleton lies on a pipe beneath it - Sinclair's - and the duffle bag next to it contains a copy of Nikola Tesla and You.

Inside the vault itself is an assortment of weapons, armor, chems, money, chips... and the fabled Treasure of the Sierra Madre: 37 gold bars worth 10,539 caps each, for a total of 389,943 caps and the single greatest collection of wealth in the Mojave Wasteland - each of which weighs 35 pounds, for a total of 1,295 pounds. There are also over 2000 .357 Magnum rounds inside a gun cabinet (not a fixed number, it's dependent on Luck and whether the Courier has Scrounger), as well as some Sierra Madre armor, reinforced.

However, the vault door seals within seconds of entrance. Lift the lockdown using the left security terminal, then use the monitor in the back to look up the word 'Vera.' This reveals that Sinclair in fact designed the Sierra Madre Vault not to protect valuables, but a small number of people as per a Vault-Tecvault through the Great War: namely himself and Vera Keyes. Learning that Dean Domino planned to rob the Sierra Madre with Vera's help changed these plans. Sinclair left a warning for Vera, and a trap for Domino: a file marked "Sinclair's Personal Accounts," the reading of which activates a system which permanently seals the vault.

If the Courier chooses to access Sinclair's personal accounts, the game will end in with a slideshow cutscene, stating how the Courier was trapped in the casino vault, eventually dying inside. The game will then load the autosave created before accessing the terminal inside the vault.

After the Courier reads the Vera entries (and without reading the personal accounts closes the terminal), Elijah will make contact. Skills of 75+ in Science, Repair, Sneak, Explosives, Barter, Speech or Lockpick can be used to persuade Elijah to enter the vault to confront the Courier personally. If one's reputation with the NCR is low enough, the Courier can ally with Elijah during this conversation. He regrets putting the collar on a potential ally and comes down to the vault. But the end slideshow starts early, detailing how the Courier and Elijah conquer the Mojave with an army of holograms and generate a second Cloud over Hoover Dam, ensuring nobody gets the power. Unfortunately, this results in another nonstandard game over.

The Courier cannot ally with Elijah unless they previously spoke to Veronica about him and exhausted all relevant conversation options.

After leaving the vault control terminal, Father Elijah will contact the Courier on a green screen behind the terminal and they're given the opportunity to further question Elijah's methods and motives. When the topic of Elijah coming down to the vault arises, the following dialogue options and skill checks (75+) are available:

"Unless you come down here, I'll destroy the vault, everything in it." - followed by choice of Explosives, Science or Repair skill checks.

"I'm not interested in the vault, I only want to leave." - followed by choice of Speech or Barter skill checks.

"Then I'll find a way to unlock the secrets of this vault, take them for myself." - followed by choice of Lockpick or Sneak skill checks.

"If you want me to wait, I'll cooperate. The Sierra Madre doesn't matter to me." He appreciates the cooperation and prompts the Courier to leave the vault and wait where he can see you. Stand at the forcefield barrier nearest the elevator and he accuses you of attempting to steal vault contents, or remain out of sight and he belittles your cowardice first. Elijah activates the security turrets, and once the Courier initiates combat, a fight to the death ensues.

With any of the first three options (he's persuaded or coerced into approaching the vault), he will arrive via the elevator, deactivate the forcefields and walk directly to the vault door. The player character has one of two options: confront Elijah and kill him, or sneak away from the vault and make one's escape to the elevator. It is also possible, although very difficult, to sneak through the door Elijah comes in through.

Hacking the security terminal (Science 100) in the vault will cause the turrets outside to turn on Elijah. However, if they kill him, the player character will not receive the Cash Out achievement/trophy (credit is only awarded for personal or companion kills, and the turrets are neutral). Destroying the turret generator (Melee or Unarmed 50) next to the terminal will disable the security turrets and cause Elijah to become hostile when he gets to the vault door.

Elijah is immune to damage as he approaches the vault, up until combat is initiated and he reactivates the forcefield barriers blocking access to the elevator. He becomes instantly aware if the Courier steps near either of the two forcefield barriers nearest the elevator, even if the Courier has 100 Sneak and is using a Stealth Boy. Elijah can also pass through the forcefield even if it is active, before or during the fight.

If the Courier is on good terms with Christine Royce when you initiate combat with Elijah, she will aid them by deactivating the turrets that are hostile to the Courier.

If the Courier is on good terms with Dean Domino when you initiate combat with Elijah, he will aid them by deactivating the speakers giving the Courier more ground to walk on without having to worry about their collar exploding.

In order to sneak past Elijah and seal him in the vault, resulting in the Safety Deposit Box achievement, simply leave the vault and retrace the route you followed to get in. Or wait when Elijah comes down and remain Hidden outside the blue forcefield barriers. When Elijah triggers the trap that seals him in the vault, he will realize the Courier tricked him and activate their collar. It will take about a minute to explode. The entrance opposite the elevator will remain open until Elijah activates security, but, as noted above, the forcefields nearest the elevator will activate automatically if approached. If one remains within the confines of the turret room barriers, whether Hidden or not, Elijah eventually activates security, turning the turrets on and sealing the Courier in while they fight.

Once Elijah is killed, or he realizes he's been tricked, the entire vault level begins to fall apart and the explosive collar is activated; it will detonate within a minute unless the Courier boards the elevator to the surface.

Reach the elevator in time, and the Courier appears at the fountain in the Villa. The Courier can then revisit any location in the Sierra Madre except the vault itself. The explosive collar will have been automatically removed upon arrival in the Villa, which makes navigating the outlying areas easier and allows exploration of previously unavailable locations.

Once the Courier exits the front gates of the villa, a slide show plays detailing the fates of his three fellow captives, ending with the Courier deposited at the abandoned Brotherhood of Steel bunker, unable to return to the Sierra Madre (except with PC console commands, finding a steel "Door to Villa"). Thus make sure everything needed was collected before leaving. The radio plays a last broadcast from Vera Keyes, bidding the Courier farewell and reflecting on the real meaning Sinclair intended for the Sierra Madre casino.

The Courier's original equipment will be returned as they walk up the stairs to leave the abandoned BoS bunker.

If the player character chooses to read Sinclair's personal accounts, they will find a letter to Dean Domino. At the end of the letter, it says "...and I will raise my glass and say 'Fortunato.'" This is a reference to Edgar Allan Poe's "The Cask of Amontillado," in which the protagonist Montresor lures his victim, Fortunato, to an underground crypt in his family catacombs, where he chains him to a wall and seals him up alive in an alcove. This is similar to how Sinclair was supposed to have trapped Dean Domino in his own grave at the bottom of the Sierra Madre. It is signed "in pace requiescat," Latin for "rest in peace," the phrase with which Poe's story ends.

PCPlaystation 3Xbox 360 There is a glitch where dying after speaking to Elijah but before reaching the elevator can cause you to reload an autosave infront of the vault monitor, but the second it loads you die. This causes a reload of the same autosave, which creates an infinite loop of dying and reloading. Saving before speaking to Elijah should fix the problem. [verified]

Playstation 3 If you are over-encumbered upon using the terminal in the back of the vault, speaking with Father Elijah will cause the dialogue to auto-skip. This bug continues to occur even if you reload from the terminal auto-save, and are not over-encumbered. [verified]

PC Upon trying to get back to the Mojave Wasteland at the end the game will crash the desktop, rendering your savegame useless. Edit: The new patch (25/04) has fixed this issue. [verified]

Xbox 360 There is a bug when opening the computer in the Vault, after completing the mission and the slide show you will be locked in the Vault, unable to get out. [verified]

Xbox 360 A bug has been reported preventing the player from leaving the abandoned BoS bunker after finishing the quest. (workaround) go to the Xbox dashboard, then to system settings, select memory, hit Y on the drive your save is on, then clear system cache. Go back to reload the game and say No to downloading the update then load your save game and you can then exit the bunker. After which you can reload the updates. [verified]

PCPlaystation 3Xbox 360 As of 5/15/2011 with patch 1.3.0.444, when trying to return to the Mojave Wasteland, the game will freeze on a black screen forcing you to reset your Xbox 360. Deleting patch 1.3.0.444 will allow you to return but the Villa will lose its "aged" texture and the slideshow will be removed. Edit: Tested on PC with most recent patch and game also crashes. [verified]

A fix to the above bug (on Hardcore mode) is making sure as you're leaving to satisfy the couriers hunger, thirst, sleep deprivation, and radiation.

On player, before trying to leave back to the Mojave, go to the console and type tcl to turn clipping off, then use the gate. When the slideshow appears, there will be no narration. Go back into the console and again, type tcl to turn clipping back on. The narration should now play and will put you back in the BoS Bunker.

PCXbox 360 A bug may cause you to continue to be poisoned for the rest of the game despite being outside the toxic cloud, if upon entering the room with the three hologram guards, you turn immediately right and go down the steps to a platform within the toxic cloud where you can find a toolbox and a holotape with the Vault turret terminal Password. Should this happen, you will not be able to leave the Sierra Madre despite achieving mission success (with enough stimpaks) as you will die during the ending slide show which one cannot skip through. If you wish to get the holotape, you should save your game before going down the steps and should the bug occur, reload that save game and try again. [verified]

Xbox 360 Bug will act as if maintenance door is still locked and closed, even if opened (Invisible Wall), effectively trapping the player until their collar blows up. The best thing to do is wait it out for a few moments and it will then let you walk through it. [verified]

Playstation 3 A glitch might occur after you've taken all 37 gold bars and leaving the vault the ending won't appear, to fix this go back into the vault then leave again. [verified]

Xbox 360 Another workable variant of the above bug- purchase demolition charges from the Vending Machine inside the Vault (15 should do the trick). Hurry out and meet Elijah before he exits onto the walkway. Then crouch on the top step next to the forcefield and toss all the Demo Charges onto the stairs you just came up. You WILL have to endure turret fire while you do this. Then proceed as noted; press against the forcefield as you destroy turrets, eventually falling in as Father Elijah runs out. Elijah hits the charges, you are protected by the forcefield, Elijah dies and you exit with plenty of time to spare. [verified]

Xbox 360 If you save near the toolbox outside of the Vault and die, you will respawn and immediately go into a death loop. Your character will appear to die from falling damage despite respawning on the gantry. Furthermore, this death loop occurs for any Sierra Madre savegame. To break this cycle, it is necessary to load a Mojave-based savegame, or exit the game completely, restart, and reload. [verified]

Xbox 360 During the ending slide show, the narrator will repeat, "We've all heard the story of the Sierra Madre" at least two times times before continuing on through the scripted sequence explaining the fate of your comrades. [verified]

Xbox 360 When Elijah comes to meet you in the vault, if you equip a Stealth Boy and sneak, unseen, into the shield of the doorway that Elijah stands behind you will be thrown through the shield to the other side of the doorway and Elijah will appear on the vault side of the doorway. The elevator will be locked and require a key until Elijah is dead. But if you find a way to kill him from that side of the door(you can use mines or plastic explosives) the Elevator will become unlocked. [verified]

Xbox 360 If you stand close enough to the forcefield where Elijah enters, you can get him to glitch you through the forcefield. It is also possible to glitch through the forcefield with all of the gold bars too. The only problem is that you have to kill father Elijah and since he cannot walk through the force field you cannot complete the quest and take the elevator back up to the hotel.(Unconfirmed)You might be able to kill Elijah with the use of land mines near the force field or if you can lure him to the force field you can shoot him through it. [verified]

PCPlaystation 3 Sometimes, if you disable the turrets before Elijah comes into the vault, he remains behind the forcefield, and you cannot kill him, thus preventing the DLCs completion. Regarding the above bug (dropping gold by the door, destroying turrets to bring Elijah into the vault and falling through the forcefield), he may remain behind the forcefield and shoot at you with his Gauss rifle, which still injures the player. You cannot damage him through the field. [verified]

PC There is a bug where if you sneak past Elijah and get to the elevator safely through the ducts, the game will crash to the desktop, losing your achievement. To fix this, you must restart the game, and load your last save. [verified]

Playstation 3 After escaping the vault and returning to the Mojave Wasteland, you can lose most of your inventory. Meaning most of you weapons, ammunition, clothing, armor, stimpak etc., will disappear from the game.You will still receive some items, 8 stimpaks 5 drained microfusion cell and some doctor's bag. To prevent this you can store all of your equipment before entering the Sierra Madre in the storage box inside the abandoned BoS bunker. [verified]

PC Sometimes after you kill Elijah the force fields will remain up, trapping the Courier in the vault until the Explosive collar detonates. [verified]

PC Opening the "personal accounts" will cause an instant game over, giving player a bad ending, and the game itself might crash, force the player to restart the computer. [verified]

PC After activating the vault control terminal, the green screen will open and close again with the message "There is no response in the intercom", making the player lose controls and not finish the quest. There is one way to fix this, by pulling up the console, and entering player.setstage 01000FC1 100. It will complete the quest, setting you free. It may be necessary to use movetoqt, as well if you cannot leave the room.(Make your load order is correct, with New Vegas first, and dead money second, or this might not work)

PC After killing Elijah the quest marker would not update.The marker would point to his body even after it said to escape. Prior to removing the collar with commands and leaving the Madre, approaching the exit would play Elijah's warning about leaving without doing what you were told.After playing the slideshow and arriving back in the bunker, the marker for the quest remained pointing towards the room with the speaker playing the broadcast. [verified]

PC When talking to Elijah on the screen in the vault, if you choose "There's something else I wanted to know," Elijah will say "Ask! You still have time." However, his voice will not be muffled as if through a projection, but will sound like he's talking to you face-to-face. [verified]

PCPlaystation 3 When going back to Christine after threading Vera's music at the Reception Terminal, there is a possibility to get infinite XP if you have Perception of 7. Initiating conversation with Christine and selecting the first dialogue option each time will get you 70xp per conversation, when passing a Perception 7 check. The conversation can be repeated infinitely.[verified]

PCXbox 360 After requesting Christine to open the door, she glitches and refuses to move. [verified]